Van Osten dazu: „I wrote and drew those sketches around 1975 and I'm so tickled to know that people still find them helpful today. It started as a slide presentation for my boss to show at the Disney meeting in Frankfurt. It went over so well that he asked me to expand on it when he returned. They printed 2000 copies and mailed it to all the Disney offices. My friend John Pomeroy asked for some to give to the animators at the studio. that was the time when the animation training program was going on. Frank Thomas saw it and used it for an animation class he was teaching at the Screen Cartoonists Guild. That's how some sketches wound up in the book that he and Ollie wrote, ‚The Illusion of Life‘.“